This disclosure is related to fabric softener compositions and to methods of manufacture thereof.
Fabric softeners (also called fabric conditioners) are used to prevent static cling and to make a fabric softer. Fabric softeners are widely used by home consumers and commercial laundries to provide softness, surface smoothness, good draping qualities, fluffiness and antistatic properties while avoiding surface greasiness or excessive build-up on the fabric. Although fabric softener technology is well known, the exact softening mechanism is not fully understood. One commonly accepted mechanism relates softness to the lubricity of the adsorbed softener on the cloth and the consequent reduction of friction between the fabric fibers. Fabric softeners are available as a liquid, as powder, as molded solids (such as bars), or as dryer sheets. They can be applied to fabrics in the washing machine, in the clothes dryer, or as a spray. Popular brand names include DOWNY (LENOR), GAIN, SNUGGLE, BOUNCE, COMFORT AND STA-SOFT.
Fabric softener compositions that can be added to the rinse water when washing household laundry normally contain, as an active substance (also called a fabric softener active), a water-insoluble quaternary ammonium compound. Commercially available fabric softener compositions are based on aqueous dispersions of water-insoluble quaternary compounds. Recently, there has been increasing interest in biodegradable active substances. Such substances include, for example, esters of quaternary ammonium compounds, so-called “esterquats,” which have at least one long-chain hydrophobic alkyl or alkenyl group interrupted by carboxyl groups.
Active substances in fabric softener compositions that impart a good soft handle to the treated textile generally have the disadvantage that they may lower the water absorbency and wickability of the textile fabric. This is troublesome in the use of 100% cotton items, such as towels and diapers, where softness and water absorbency properties are both desired. The problem is generally exacerbated in more hydrophobic synthetic fibers, such as polyester, polypropylene and nylon and blends thereof with other synthetic and natural fibers. The problem may be so severe that many garments made from high performance fabrics where the ability to rapidly wick water from the skin and dry quickly actually include warnings against using any fabric softener during the laundering process because the use of the fabric softener may destroy the water-absorbency, rewettability and wickability properties of the fabric—properties key to their performance. The disadvantage of reduced water absorbency is often highly pronounced in the case of certain active substances, such as the fatty acid quats.